speadersheet

--Included libs:
--delegate (by me)
local function delegate()
	return setmetatable({func = {},
	add = function(self,func)
		checkTypes({self,func},{"table","function"})
		self.func[#self.func+1] = func
	end,
	sub = function(self,func)
		checkTypes({self,func},{"table","function"})
		for i=1,#self.func do
			local v = self.func[i]
			if v == func then
				table.remove(self.func,i)
			end
		end
	end,
	},
	{__call = function(tbl,...)
		if type(tbl.func) == "table" then
			local c,r = 0,{}
			for k,v in pairs(tbl.func) do
				if type(v) == "function" then
					c = c+1
					r[c] = {pcall(v,...)}
				end
			end
			return c,r
		end
	end,
	__add = function(self,func)
		self:add(func)
	end,
	__sub = function(self,func)
		self:sub(func)
	end,
	})
end
--Setup vars:
	--general vars
	local filepath = ""
	--display vars
	local scroll = {0,0}
	local showncolumncount = 10
	local w,h = term.getSize()
	local gridw, gridh = w-2, h-2 --why not put this here :P
	local gridx, gridy = 4,2
	local defaultColumnWidth = 10
	--selection vars
	local selected = {1,1} --selected cell position
	local endselection = {}
	local multiselect = false
	--file content vars
	local grid = {}
	local columnWidths = {}
	--copy/paste vars
	local clipboard = {}
	--theme vars
	local theme = term.isColor() and {
		default = {colors.white, colors.black},
		selected = {colors.green, colors.white},
		multiselected = {colors.lime, colors.black},
		menu = {colors.green, colors.white},
		border = {colors.lightGray, colors.black}
	} or {
		default = {colors.black, colors.white},
		selected = {colors.white, colors.black},
		multiselected = {colors.gray, colors.black},
		menu = {colors.white, colors.black},
		border = {colors.lightGray, colors.black}
	}
--Handle args:
local tArgs = {...}
if #tArgs < 1 then --not enough args
	print[[
Usage:
speadersheet <filename>
]]
	error("",0)
end
filepath = tArgs[1]
--Local functions:
local function selectColors(name) --selects colors, args: name of theme
	local cols = theme[name]
	term.setBackgroundColor(cols[1])
	term.setTextColor(cols[2])
end
local function redrawGrid() --redraws grid  and bottom line
	--this is the function that will need lots of optimization probably
	local drawing = {scroll[1], scroll[2]} --which cell are we drawing (to get the content)
	for y=gridy, gridh + gridy - 1 do
		drawing[2] = drawing[2] + 1
		drawing[1] = scroll[1]
		term.setCursorPos(gridx, y)
		for i=1,showncolumncount do
			drawing[1] = drawing[1] + 1
			local cwidth = columnWidths[drawing[1]] or defaultColumnWidth
			selectColors((selected[1] == drawing[1] and selected[2] == drawing[2]) and "selected" or (multiselect and (selected[1] >= drawing[1] and selected[2] >= drawing[2]) and (endselection[1] <= drawing[1] and endselection[2] <= drawing[2])) and "multiselected" or "default")
			local text = grid[drawing[1]] and grid[drawing[1]][drawing[2]] and grid[drawing[1]][drawing[2]] or ""
			term.write(text .. (#text < cwidth - 1 and string.rep(" ",(cwidth - 1) - #text) or ""))
			if selected[1] == drawing[1] and selected[2] == drawing[2] then
				local oldx,oldy = term.getCursorPos()
				term.setCursorPos(1,h)
				selectColors("menu")
				--This is repeated because of functions later
				local realtext = grid[drawing[1]] and grid[drawing[1]][drawing[2]] and grid[drawing[1]][drawing[2]] or ""
				term.write(realtext .. (#realtext < w and string.rep(" ",w - #realtext) or ""))
				term.setCursorPos(oldx,oldy)
			end
			selectColors("border")
			term.write(" ")
		end
	end
end
local function redrawMenu() --redraws column and row numbers
	--redraw top column numbers
	do
		local drawing = scroll[1]
		term.setCursorPos(gridx, 1)
		selectColors("menu")
		term.clearLine()
		term.setCursorPos(gridx, 1)
		for i=1,showncolumncount do
			drawing = drawing + 1
			local cwidth = columnWidths[drawing] or defaultColumnWidth
			term.write(drawing)
			term.write(string.rep(" ",cwidth - #tostring(drawing)))
		end
	end
	--redraw line numbers
	local drawing = scroll[2]
	for y=gridy, gridh + gridy - 1 do
		drawing = drawing + 1
		term.setCursorPos(1, y)
		term.write(tostring(drawing) .. string.rep(" ",3 - #tostring(drawing)))
	end
end
local function checkScroll() --scrolls if needed
	local scrolled = false
	--horizontal:
	local cx = gridx
	local count = 0
	local drawing = scroll[1]
	for i=1,w do -- count how many columns are on screen
		drawing = drawing + 1
		local cwidth = columnWidths[drawing] or defaultColumnWidth
		cx = cx + cwidth
		count = count + 1
		if cx >= w then break end
	end
	showncolumncount = count
	while selected[1] - scroll[1] < 1 do
		scroll[1] = scroll[1] - 1
		scrolled = true
	end
	while selected[1] > scroll[1] + count do
		scroll[1] = scroll[1] + 1
		scrolled = true
	end
	--vertical:
	while selected[2] - scroll[2] < 1 do
		scroll[2] = scroll[2] - 1
		scrolled = true
	end
	while selected[2] > scroll[2] + gridh do
		scroll[2] = scroll[2] + 1
		scrolled = true
	end
	if scrolled then
		redrawGrid()
		redrawMenu()
	end
end
local function save() --saves persistant data
	local h = fs.open(filepath,"w")
	local cont = textutils.serialize{
		grid,
		selected,
		endselection,
		multiselect,
		columnWidths,
		showhelp,
		scroll
	}
	h.write(cont)
	h.close()
end
local function reload() --loads persistant data
	if fs.exists(filepath) then
		local h = fs.open(filepath,"r")
		local cont = textutils.unserialize(h.readAll())
		h.close()
		grid = cont[1] or {}
		selected = cont[2] or {1,1}
		endselection = cont[3] or {1,1}
		multiselect = cont[4]
		columnWidths = cont[5] or {}
		showhelp = cont[6] or true
		scroll = cont[7] or {0,0}
	end
end
local function cancel() --cancels multiselection
	if multiselect then
		multiselect = false
	end
	endselection = {selected[1], selected[2]}
end
local function initMultiselect() --inits multiselection if needed
	if not multiselect then
		multiselect = true
		endselection = {selected[1], selected[2]}
	end
end
local function convertSelection() -- converts multi/single selection to a smaller sub grid and returns it
	local subx, suby = 1,1
	local subgrid = {}
	for x = endselection[1], selected[1] do
		subgrid[subx] = {}
		for y = endselection[2], selected[2] do
			subgrid[subx][suby] = grid[x] and grid[x][y] and grid[x][y] or ""
			suby = suby + 1
		end
		suby = 1
		subx = subx + 1
	end
	return subgrid
end
local function pasteSubgrid(subgrid, x, y) --pastes subgrid in main grid
	for i=#subgrid, 1, -1 do
		local line = subgrid[i]
		for j = #line, 1, -1 do
			local cell = line[j]
			if not grid[x + i - 1] then
				grid[x + i - 1] = {}
			end
			grid[x + i - 1][y + j - 1] = cell
		end
	end
end
local function deleteSelection()
	for x = endselection[1], selected[1] do
		for y = endselection[2], selected[2] do
			if grid[x] then
				grid[x][y] = ""
			end
		end
	end
end
reload()
--Key-event table:
local handler = {
	--[[
		movement:
		arrow keys = move
		p/l = multiselect (move right bottom corner right/down)
		enter = edit
		home = first column
		end = first row
		page up = page up
		page down = page down
		general:
		s = save
		q = exit
		copy/paste:
		c = copy
		v = paste
		x = cut
	]]
	key = {
		[keys.up] = function() cancel() selected[2] = selected[2] > 1 and selected[2] - 1 or 1 redrawGrid() end;
		[keys.down] = function() cancel() selected[2] = selected[2] + 1 redrawGrid() end;
		[keys.left] = function() cancel() selected[1] = selected[1] > 1 and selected[1] - 1 or 1 redrawGrid() end;
		[keys.right] = function() cancel() selected[1] = selected[1] + 1 redrawGrid() end;
		[keys.home] = function() cancel() selected[1] = 1 redrawGrid() end;
		[keys["end"]] = function() cancel() selected[2] = 1 redrawGrid() end;
		[keys.pageUp] = function() cancel() selected[2] = selected[2] > gridh-1 and selected[2] - (gridh-1) or 1 redrawGrid() end;
		[keys.pageDown] = function() cancel() selected[2] = selected[2] + gridh - 1 redrawGrid() end;
		[keys.p] = function() initMultiselect() selected[1] = selected[1] + 1 redrawGrid() end;
		[keys.l] = function() initMultiselect() selected[2] = selected[2] + 1 redrawGrid() end;
		[keys.enter] = function()
			term.setCursorPos(1,h)
			selectColors("menu")
			term.clearLine()
			term.setCursorPos(1,h)
			if not grid[selected[1]] then
				grid[selected[1]] = {}
			end
			grid[selected[1]][selected[2]] = read()
			redrawGrid()
			redrawMenu()
		end;
		[keys.s] = function()
			save()
		end;
		[keys.q] = function()
			term.setBackgroundColor(colors.black)
			term.setTextColor(colors.white)
			term.clear()
			term.setCursorPos(1,1)
			sleep(0)
			error("",0)
		end;
		[keys.c] = function()
			clipboard = convertSelection()
		end;
		[keys.v] = function()
			pasteSubgrid(clipboard, selected[1], selected[2])
			redrawGrid()
		end;
		[keys.x] = function()
			clipboard = convertSelection()
			deleteSelection()
			redrawGrid()
		end;
	}
}
--Main loop:
term.clear()
redrawGrid()
redrawMenu()
while true do
	local event,param = os.pullEvent()
	if handler[event] and handler[event][param] then
		handler[event][param]()
		checkScroll()
	end
end